Porous zinc oxide thin-film for substrate of dye-sensitized solar cell, zinc oxide/dye composite thin-film for photoelectrode and dye-sensitized solar cell

Abstract

The invention provides a porous zinc oxide thin film for a substrate of a dye-sensitized solar cell having pores formed by mixing an electrolytic solution containing a zinc salt with a template compound in advance in the presence of a desired substrate, applying cathodic electrodeposition for uniform and forcible material transport on the surface of the substrate, forming a zinc oxide thin film comprising the template compound adsorbed on the inner surface of the thin film on the substrate, and applying means for desorbing the template compound from the zinc oxide thin film; a zinc oxide / dye composite thin film for a photoelectrode prepared by adsorbing the dye in the pores; and a dye-sensitized solar cell using the zinc oxide / dye composite thin film as the photoelectrode material.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a porous zinc oxide thin film for a substrate of a dye-sensitized solar cell obtained by cathodic electrodeposition in the presence of a template compound and a zinc oxide / dye composite thin film suitable as a photoelectrode material of the dye-sensitized solar cell obtained by allowing the porous zinc oxide thin film to adsorb the dye, and a method for producing thereof, and a dye-sensitized solar cell using the zinc oxide / dye composite thin film as the photoelectrode material. [0003] 2. Description of the Related Art [0004] Solar cells are noticed today as an environmentally sound power generation technology using inexhaustible resources. Since the report by Graetzel in 1991 (Nature, 353, 737), dye-sensitized solar cells capable of producing with a lower cost than conventional silicon solar cells have been a focus of worldwide attention. The dye-sensitized solar cell is produced using a tr...

AI Technical Summary

Benefits of technology

"The present invention relates to a dye-sensitized solar cell with a porous zinc oxide thin film as the substrate. The invention provides a method for depositing a template compound on the inner surface of the zinc oxide thin film and then desorbing the template compound to form pores in the thin film. The template compound is a compound that is adsorbed on the inner surface of the thin film and is reduced in the process. The invention also provides a method for desorbing the template compound using an aqueous base solution. The resulting porous zinc oxide thin film has a high specific surface area and allows for the formation of many pores on the surface, which increases the surface area of the thin film. The method for depositing the zinc oxide thin film is particularly important for making the process practical. The invention also provides a dye-sensitized solar cell with the porous zinc oxide thin film as the substrate, which has improved performance."

Problems solved by technology

Although the theoretical limit of photoelectric conversion ratio of such dye-sensitized solar cell is considered to be 33%, a sufficient photoelectric conversion ratio has not been attained yet.

However, most of the conventionally proposed dye-sensitized solar cell uses a baked semiconductor, and the transparent substrate is restricted to a heat resistant substance in the dye-sensitized solar cell using the baked semiconductor.

Consequently, selection of the transparent substrate is restricted and it is difficult to use inexpensive plastics as the transparent substrate.

While the baking process is not needed in the dye-sensitized solar cell using a zinc oxide thin film prepared by electrodeposition as the semiconductor without adding any dyes, the surface area of the thin film is small and a sufficient amount of the dye cannot be introduced after forming the thin film.

Therefore, it was a problem that the photoelectric conversion ratio can be hardly enhanced.

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